Declaration: 
int strcmp(char s1[], char s2[], int s1_index=0, int s2_index=0); 
Description 
The strcmp function compares lines s1 and s2 letter-by-letter and returns the result of the search. 
Returned value 
The strcmp function returns the following values of comparison result: 
       Value        Meaning 
       ------------------------------- 
       < 0          s1 is less than s2 
       = 0          s1 is equal to s2 
       > 0          s1 is greater than s2 
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